Crazy Laptop problem - HP Envy x360

[John Jenson]

Re: Crazy Laptop problem - HP Envy x360

Yes, it will be fine.

Just wondering because this laptop uses BitLocker to encrypt the data and I don't want to lose data. Of course I will definitely back up the data before I do it; I just don't want to have to do a reinstall.

[mon2]

Re: Crazy Laptop problem - HP Envy x360

No experience in that area so what for other comments.

[reformatt]

Re: Crazy Laptop problem - HP Envy x360

Dump your Bitlocker recovery key from Windows settings or via manage-bde command prompt to a txt file on usb etc. Bios updates usually suspend encryption anyway, but always safe to have your key regardless.

[John Jenson]

Re: Crazy Laptop problem - HP Envy x360

Okay, replaced the BIOS. Did not fix the problem.

[John Jenson]

Re: Crazy Laptop problem - HP Envy x360

So no one has any ideas on what could be the problem? Could I possibly be the first one to ever have this problem with an HP laptop?

[reformatt]

Re: Crazy Laptop problem - HP Envy x360

Normally things like this it's a failed power button. CMOS reset the laptop turns itself on, so power button response would be next thing to check. You'd probably need a schematic to see what is going on around the EC if that checks out.

[John Jenson]

Re: Crazy Laptop problem - HP Envy x360

Normally things like this it's a failed power button. CMOS reset the laptop turns itself on, so power button response would be next thing to check. You'd probably need a schematic to see what is going on around the EC if that checks out.

It's obviously not the power button based on the symptom.

If I hold the power button down when it's running, the computer powers off. If I hit it again, it boots and the power button lights. It's just if I do a normal Windows shutdown, it turns off and won't come on again (charging light goes out as well). I've searched around this forum and no one has ever had such a problem.

I would love to get this schematic, but from where?

[John Jenson]

Re: Crazy Laptop problem - HP Envy x360

I believe I've found the problem. I was measuring switching supply voltages with my multimeter and measured 5v, 3.3v and then I measured a 4v. 4v seems like an odd ball voltage, so I broke out the scope and found a square wave on the coil. This circuit is the charge controller. Apparently the ISL9538B charge controller is acting funny. I'll have to wait 3 weeks to replace it due to China delivery.

[mcplslg123]

Re: Crazy Laptop problem - HP Envy x360

Apparently the ISL9538B charge controller is acting funny-Can you elaborate a bit more why you think so?

[John Jenson]

Re: Crazy Laptop problem - HP Envy x360

Apparently the ISL9538B charge controller is acting funny-Can you elaborate a bit more why you think so?

I thought I did that already. I was getting a square wave on the coil instead of a smooth voltage.

[mcplslg123]

Re: Crazy Laptop problem - HP Envy x360

I thought I did that already. I was getting a square wave on the coil instead of a smooth voltage.

Did you measured booth sides of the coil with scope?

[John Jenson]

Re: Crazy Laptop problem - HP Envy x360

Did you measured booth sides of the coil with scope?

You know I did. I was getting the same phase signal on both sides, which is why I said the circuit was acting funny.

I also checked the inductor (2R2) with an LCR meter to not only make sure it wasn't open, but to make sure it was still 2.2uh. I removed the inductor so I could check the dual MOSFETs, which appeared to be okay and for good measure, I (because I had so much time on my hands) swapped the 2R2 inductor with the one in the 5v circuit and there was no change. The 5v still worked and the charging power supply still put out a square wave. There is a lot more testing I would do if I could get my hands on schematics; but since there aren't any, I am left with my own intuition.

As far as the ISL9538B. I was able to get a limited datasheet for that chip, however, there are no pin numbers as it seems to be privileged information that you need secret clearance to obtain. I tried getting a full datasheet from Renesas Electronics Corporation. I had to register on their site and then after filling out all the info, waiting and activating my account, I then tried to get the datasheet only to be told that I with be contacted in 24 - 48 hours if I qualify to obtain such secret info. I guess this company is paranoid that I'm going to reverse engineer their products and put them out of business.

I could buy another chip on ebay for about 6 times the price and get it within the week, which I would do if I was in such a big hurry to get this fixed, but since I'm a week away from going on a 2 week vacation, I ordered from China as it will be here when I return. I ordered 10 pieces of the chip and another 10 pieces of the dual MOSFET, just in case.

I'll definitely come back here and update you all with my results.

[mcplslg123]

Re: Crazy Laptop problem - HP Envy x360

@John, see people with different levels of skills come here-some have a good grasp but some are really novice. Its difficult to guess the skill levels of the OP unless and otherwise he/she is regular on the forum. thats why i wanted to make sure your conclusion is right. Lets wait for the chip.

However, it'll be nice if you measure UG/LG/Phase pins with DSO. I think we can expect a peak of 24V approx on UG with pulse on DSO.

[John Jenson]

Re: Crazy Laptop problem - HP Envy x360

@John, see people with different levels of skills come here-some have a good grasp but some are really novice. Its difficult to guess the skill levels of the OP unless and otherwise he/she is regular on the forum. thats why i wanted to make sure your conclusion is right. Lets wait for the chip.

However, it'll be nice if you measure UG/LG/Phase pins with DSO. I think we can expect a peak of 24V approx on UG with pulse on DSO.

A little background on me: I started out as an electronic technician back in the 80's and slowly evolved into a self taught embedded systems engineer. I was designing embedded systems with 8051's and derivatives in assembly language and ANSI C. Worked for a few big companies and then went solo after 2008. I've fixed a lot of things in my days, including laptops, although fixing laptops was never my specialty; which is why I came here, where I can expect technicians who do specialize in them.

I measured those voltages at the gates of the MOSFETs and they looked healthy. I wanted to really check the circuit with respect to phase, but because the datasheet didn't show any pin numbers and the circuit eventually died completely in midst of my testing , it kind of stopped me. Yeah, I could have buzzed out some of the pins with a continuity tester, but it really wouldn't buy me much at that point. I am pretty convinced the chip is bad and will replace it once it gets here and if need be I could replace a MOSFET or two as well.

[John Jenson]

Re: Crazy Laptop problem - HP Envy x360

I replaced the charging chip and the two dual MOSFET's. The charging circuit is back to the way it was when I suspected it (before I killed it), but the laptop still has the same problem. I shouldn't have jumped the gun on the charging circuit, but I assumed it was supposed to work just like other switching supplies where the voltage on the coil will always be a stable voltage. However, this charging chip is a boost/buck converter (using 4 MOSFET's). When battery power is low, it goes into buck mode (only 2 MOSFET's are switching) and the voltage on the coil is stable (like other 2 MOSFET switching circuits), but when the battery is (almost) fully charged, it goes into boost/buck mode, where there are pulses on the coil as all 4 MOSFET's are firing; this is normal for this circuit. I couldn't get the full schematic with the pinouts for the ISL9538, but I found out the ISL9238 is electrically the same and I was able to use the datasheet for that as it was available. So the charging circuit was working correctly the whole time until I killed it, probably with a slip of a probe. At least I learned something about these boost/buck circuits that (I assume) aren't very common on laptops; and can share that with others.

Now I'm back to the original problem. I guess the next thing I will try is to physically reprogram the BIOS. Anyone have a BIOS for this board? Or do I have to repost it in another thread? I will be getting a RT809F programmer today, which should (hopefully) be able to reprogram this BIOS.

[Vesko356]

Re: Crazy Laptop problem - HP Envy x360

Anyone have a BIOS for this board? Or do I have to repost it in another thread?

Yes, you must request this at the "BIOS Requests ONLY!" subsection.
https://www.badcaps.net/forum/forumdisplay.php?f=40

Reminder: rules and organization of this section
https://www.badcaps.net/forum/showthread.php?t=117483

.

[todenkopf]

Re: Crazy Laptop problem - HP Envy x360

Check resistor dividers on CSOP/CSON pins. Unplugging the battery you're kind of resetting some OVC protection and it looks to me that the problem lies in incorrect measurement of the current by the charger IC.